Desktop Functions:

   Smart Device Functions:

Show Recent Changes
Subscribe (RSS)
Misc. Pages
Helpful Tools
Suggested Reading
Website TODO List
Download Visual Studio Add-In

VirtualFreeEx (kernel32)

C# Signature:

[DllImport("kernel32.dll", SetLastError=true, ExactSpelling=true)]
static extern bool VirtualFreeEx(IntPtr hProcess, IntPtr lpAddress,
   int dwSize, AllocationType dwFreeType);

[DllImport("kernel32.dll", SetLastError=true, ExactSpelling=true)]
public static unsafe extern bool VirtualFreeEx(
   IntPtr hProcess, byte* pAddress,
   int size, AllocationType freeType);

VB Signature:

<DllImport("kernel32.dll")> _
Public Shared Function VirtualFreeEx(ByVal hProcess As IntPtr, _
                      ByVal lpAddress As IntPtr, _
                      ByVal dwSize As Integer, _
                      ByVal dwFreeType As AllocationType) As Boolean
End Function

Boo Signature:

[DllImport("kernel32.dll", SetLastError : true, ExactSpelling : true)]
static def VirtualFreeEx(hProcess as IntPtr, lpAddress as IntPtr, dwSize as int, freeType as AllocationType) as bool:

User-Defined Types:

public enum AllocationType
     Commit = 0x1000,
     Reserve = 0x2000,
     Decommit = 0x4000,
     Release = 0x8000,
     Reset = 0x80000,
     Physical = 0x400000,
     TopDown = 0x100000,
     WriteWatch = 0x200000,
     LargePages = 0x20000000

enum AllocationType:
     Commit = 0x1000
     Reserve = 0x2000
     Decommit = 0x4000
     Release = 0x8000
     Reset = 0x80000
     Physical = 0x400000
     TopDown = 0x100000
     WriteWatch = 0x200000
     LargePages = 0x20000000



Tips & Tricks:

Please add some!

Sample Code:

Please add some!

Alternative Managed API:

The ManagedWindowsApi project ( provides a ProcessMemoryChunk class to allocate and access memory of a different process.


Please edit this page!

Do you have...

  • helpful tips or sample code to share for using this API in managed code?
  • corrections to the existing content?
  • variations of the signature you want to share?
  • additional languages you want to include?

Select "Edit This Page" on the right hand toolbar and edit it! Or add new pages containing supporting types needed for this API (structures, delegates, and more).

Access directly from VS:
Terms of Use
Edit This Page
Find References
Show Printable Version